ABSTRACT
The beginning of the microbiological concept can be differently dated according to the values placed on the various discoveries that opened the paths. The student of the progress of clinical medicine becomes aware of a special characteristic that underwent a marked development: namely, the improvement in the field of diagnosis, thanks to the steady improvement in research methods and accomplishments. This in turn brought about a closer connection between clinical medicine and pathology, which was largely responsible for these improvements. In the advancement of knowledge of internal medicine in the second half of the century, when the laboratory specialties were making their most striking contributions, the german and austrian universities took a very prominent part. One of the greatest masters of French clinical medicine was Armand trousseau, the first in Paris to practise tracheotomy, thoracentesis, and intubation.
